We propose to continue our productive studies on external eye diseases caused by chlamydial and viral agents, and etiologically and epidemiologically related infections. We plan broad, multidisciplinary investigations pertaining to diagnosis, immunology, treatment and control of infectious eye diseases which are important causes of human blindness. We shall concentrate particularly on chlamydial eye infections caused by different immunotypes of chlamydiae of genital or ocular origin on herpetic keratoconjunctivitis and on systemic aspects of herpesvirus infections, originating in the genital tract or in the eye, on adenovirus ocular infections, and on infections of as yet undefined etiology. We shall continue to study biologic and immunologic features of etiologic agents, the clinical and immunologic aspects of host responses in man, the dynamics of drug treatment (including controlled treatment trials), and epidemiologic features which determine behavior of the infections in various geographic and social environments. We bring to these studies specialized skills in ophthalmology, microbiology, virology, immunology, epidemiology, and chemotherapy as represented by various members of our group. We hope to contribute materially in the future, as we have in the past, to improved understanding of host-parasite relationships and mechanisms of control of a number of serious external eye diseases.